1. Field of the Invention
The present invention relates to a method for producing rollers and sleeves for chains, in particular for roller chains and sleeve-type chains.
2. Description of the Related Art
In roller chains and sleeve-type chains, the chain links include sleeves that are secured in recesses of the links. In a roller chain, in addition loose rollers are guided by way of the sleeves. In that way, better roll-off performance between the teeth of a sprocket wheel and the chain can be achieved.
It is known to make the rollers and sleeves from a sheet metal material, in particular strip material. To that end, in a known method the sheet metal material is rolled into a cylindrical form, in order to form a roller or sleeve. In accordance with another known method, the rollers and sleeves are extruded. Those known manufacturing methods are very elaborate and cost-intensive due in particular to the fact that seamless fabrication is not possible, so that the seams have to be reworked. Furthermore, with the known methods, in particular rolling methods, it is not possible to produce an ideal circular shape nor a defined diameter of the rollers and sleeves. In addition, because alignment of the butt joint is necessary, the strength of the produced rollers and sleeves is reduced.
An object of the present invention is to provide an improved method for producing rollers and sleeves of the type identified above so that fabrication-optimized production is made possible.